ANTENNA DEVICE AND VEHICLE COMPRISING AN ANTENNA DEVICE

Abstract

Disclosed is an antenna device comprising at least two antennas, designed for transmitting and/or receiving electromagnetic waves, and a circuit board device, wherein the antennas are arranged on the same circuit board device, the circuit board device comprises at least one decoupling layer through which a parasitic coupling of the antennas is reduced. The circuit board device comprises at least one upper substrate layer on which at least one metal strip with predetermined dimensions is arranged, wherein the metal strip is separated from the at least one decoupling layer by at least one upper substrate layer.

Claims

1. An antenna device, comprising: at least two antennas designed for transmitting and/or receiving electromagnetic waves, and a circuit board device, wherein the antennas are arranged on the same circuit board device, the circuit board arrangement comprises at least one decoupling layer through which a parasitic coupling of the antennas is reduced, characterized in that, the circuit board device comprises at least one upper substrate layer on which at least one metal strip with predetermined dimensions is arranged, wherein the metal strip is separated from the at least one decoupling layer by the at least one upper substrate layer.

2. The antenna device as claimed in claim 1, wherein the at least one decoupling layer comprises a high-impedance structure.

3. The antenna device as claimed in claim 1, wherein the at least one decoupling layer comprises an incomplete floor structure.

4. The antenna device as claimed in claim 1, wherein the at least one metal strip is aligned toward a longitudinal direction to the at least two antennas.

5. A motor vehicle with at least one antenna device as claimed in claim 1.

6. The antenna device as claimed in claim 1, wherein the at least one decoupling layer comprises a high-impedance structure; and the at least one decoupling layer comprises an incomplete floor structure; and the at least one metal strip is aligned toward a longitudinal direction to the at least two antennas.

7. A motor vehicle with at least one antenna device as claimed in claim 6.

8. A motor vehicle with at least one antenna device as claimed in claim 2.

9. The antenna device as claimed in claim 2, wherein the at least one decoupling layer comprises an incomplete floor structure.

10. A motor vehicle with at least one antenna device as claimed in claim 9.

11. The antenna device as claimed in claim 9, wherein the at least one metal strip is aligned toward a longitudinal direction to the at least two antennas.

12. A motor vehicle with at least one antenna device as claimed in claim 11.

13. The antenna device as claimed in claim 3, wherein the at least one metal strip is aligned toward a longitudinal direction to the at least two antennas.

14. A motor vehicle with at least one antenna device as claimed in claim 13.

15. A motor vehicle with at least one antenna device as claimed in claim 3.

16. A motor vehicle with at least one antenna device as claimed in claim 4.

Description

[0024] An exemplary embodiment of the invention is described below. In this respect:

[0025] FIG. 1 shows an antenna device;

[0026] FIG. 2 shows a plan view of the antenna device;

[0027] FIG. 3 shows an antenna device without a metal strip;

[0028] FIG. 4 shows the antenna device with a metal strip;

[0029] FIG. 5 shows a profile of the S12 parameter for antennas of an antenna device; and

[0030] FIG. 6 shows a comparison between two curves of the S12 parameter.

[0031] The exemplary embodiment explained below is a preferred embodiment of the invention. In the exemplary embodiment, the described components of the embodiment each represent individual features of the invention that should be considered independently of one another, and that each also develop the invention independently of one another and can therefore also be considered to be part of the invention individually or in a combination other than that shown. Furthermore, the embodiment described can also be supplemented by further features of the invention that have already been described.

[0032] In the figures, elements with the same function are each provided with the same reference signs.

[0033] FIG. 1 shows an antenna device. The antenna device 1 can comprise at least two antennas 2 that can be arranged on one side of the circuit board device 3 of the antenna device 1 and that can have a distance from one another. The antennas 2 can, for example, be monopole antennas that can be connected to a respective antenna terminal 4. It can be provided that the antennas 2 are fed through the respective antenna terminal 4 in order to transmit electromagnetic waves in a respective frequency spectrum. It can be provided that the frequency spectra of the two antennas 2 overlap or are identical. The two antennas 2 can be controlled by an integrated circuit 5 that can be arranged on the same circuit board device 3 as the antennas 2.

[0034] The circuit board device 3 can comprise a decoupling layer 6. The decoupling layer can be provided for the purpose of reducing an electromagnetic coupling of the two antennas 2 by parasitic waves. The parasitic waves can, for example, be surface components of the electromagnetic waves radiated by the antennas 2, that are guided along the circuit board device 3. The decoupling layer 6 can comprise a high-impedance structure 7. The high impedance structure 7 can have a periodic arrangement of high-impedance elements 8. It can be provided that the high-impedance elements 8 can be what are known as mushroom structures. The high-impedance elements 8 can be arranged on a ground layer 9 of the decoupling layer 6. The high-impedance elements 8 can comprise a respective connecting element 10 that can be arranged in a substrate layer 11 of the decoupling layer 6 in order to connect a metal surface 12 arranged parallel to the ground layer 9 on the substrate layer 11. The dimensions of the high-impedance elements 8 and a material of the substrate layer 11 can be chosen in such a way that a respective high-impedance element 8 can exhibit a predetermined capacitance and a predetermined inductance. Resonances can occur in the decoupling layer 6 at specific frequencies as a result. At these frequencies, the decoupling layer 6 can exhibit higher impedances, whereby the ability of the parasitic waves to propagate is reduced. The frequencies are to be chosen in the frequency range of the electromagnetic waves that are to be suppressed.

[0035] At least one upper substrate layer 13 can be arranged on the decoupling layer 6. The substrate layer 13 can consist of a dielectric material. At least one metal strip 14 can be arranged on the substrate layer 13. The metal strip 14 can, for example, be a foil glued to the substrate layer 13, or a region that is coated with metal. The metal strip 14 can be arranged between the antennas 2. The at least one metal strip 14 and the upper substrate layer 13 can have dimensions that can shift a frequency range of the decoupling layer 6 into a lower frequency region.

[0036] FIG. 2 shows a plan view of the antenna device 1. The antenna device can comprise at least two antennas 2. The metal strip 14 can be arranged on the upper substrate layer 13 between the antennas 2. The decoupling layer 6, which can comprise the high-impedance structure 7, can be arranged under the upper substrate layer 13. The high-impedance elements 8 of the high-impedance structure 7 can be arranged periodically. The metal surfaces of the high-impedance elements 8 can have a predetermined shape, for example that of a swastika, a cross or a rectangle. The metal surfaces of the high-impedance elements 8 can have dimensions of 4.8 mm * 4.8 mm * 0.8 mm. The width of the metal strip can be 2.3 mm. The upper substrate layer 13 can have a thickness of 1.3 mm. The antenna device 1 can, for example, be arranged in a motor vehicle 15.

[0037] FIG. 3 shows an antenna device 1′, wherein the circuit board device 3′ can comprise the decoupling layer 6′ with the high-impedance structure 7′. The antenna device 1′ does not have any metal strips 14′ between the two antennas 2′. The antennas 2′ can be monopole antennas.

[0038] FIG. 4 shows the antenna device 1. The antenna device can be in accord with the antenna device 1′ in FIG. 3, wherein the antenna device 1, in contrast to the antenna device 1, can comprise the metal strip 14 between the two antennas 2. The metal strip can comprise copper, and can have dimensions of 16 mm by 3.7 mm.

[0039] FIG. 5 shows a profile of the S12 parameters for antennas 2′ of an antenna device 1′, the circuit board device 3′ of which comprises neither the decoupling layer 6′ with the high-impedance structure 7′, nor the metal strip 14′. The S21 parameters can describe the transmission of an electromagnetic wave from one of the antennas 2′ to another of the antennas 2′. The S12 parameter is plotted against the frequency f. The curve shows a relatively constant profile over all frequencies f.

[0040] FIG. 6 shows a comparison between two curves of the S12 parameter. Curve I shows the profile of the S12 parameter of the antenna device 1′ of FIG. 3. This comprises the decoupling layer 6′, but not a metal strip. Curve II shows the curve of the S12 parameter of the antenna device 1 of FIG. 4. This antenna device 1 comprises the decoupling layer 6 and the metal strip 14. Both curves I, II show a characteristic frequency range fI, fII with low values of the S12 parameter. The profile of the curve II has a similar shape. The drop is nevertheless more marked, and is shifted by about 0.5 GHz toward lower frequencies.

[0041] Overall, the example shows how the invention makes it possible to influence the frequency range of a decoupling layer.